2019 Research Opportunities

X-rays scans are surprisingly bad at determining whether a particular bone is prone to fracture. Our group works on providing complementary chemical information about bones using vibrational (Raman) spectroscopy. 785-nm light interrogates the femurs and tibiae of mice by diffusing through overlying skin and muscle, scattering off of the bone, and diffusing back to the surface. Some of the scattered light comes back at longer wavelengths that encode information about the bone’s mineral and protein composition. REU students will help to extend this proven method to live-mouse measurements that can be performed over many weeks on animals undergoing various treatments related to bone research on humans.

Organelle size monitoring in single biological cells

Our group is building a microscope that acquires complex-field images of biological cells. A computational Fourier transform enables us to calculate the angular distribution of scattered light by each individual cell. This distribution, in turn, enables us to estimate the size distribution of the organelles in the cell. An REU student will assist in all aspects of the instrument development, culminating in experiments that monitor cells over time as they are exposed to various chemical stimuli. Ideally, this will result in data that reveal early changes in cells that are not detectable using standard imaging techniques.

A quantum single photon source (SPS) is highly desirable for applications in quantum information processing and secure communication. An ideal SPS should emit single photons deterministically or on-demand, and each photon should be indistinguishable with a high repetition rate and a high beta factor, which is the collection efficiency of the output photon into a desired electromagnetic mode. A platform for a SPS consists of a material and possibly a photonic structure that tailors the SPS emission properties. Particularly attractive for SPSs are solid-state quantum emitters since they can seamlessly integrate with nanophotonic devices and can serve as on-chip sources of quantum light in future integrated quantum photonic applications.

This REU project will focus on characterizing the optical properties of novel defect-based SPSs in atomically thin semiconductors. Recently we have discovered these single to few atom thick layers (the semiconducting analog of graphene) support intrinsic defects that can localize excitons and serve as a source of single photons. In parallel, the student will pursue approaches to tailor the radiative dynamics of the SPS by sculpting the local optical density of states via proximal nanophotonic structures. These devices can be both passive and active engendering a great deal of control and functionality to the SPS.

Name: Robert BoydDepartment: The Institute of OpticsResearch area: Quantum communication

We are studying QKD based on encoding in the orbital angular momentum (OAM) degree of freedom of light. OAM has enormous potential for use in high-capacity QKD, essentially because of the very large information content available through this sort of encoding. Basically, the OAM states reside in an infinite dimensional Hilbert space; there is thus no fundamental limit to how many bits of information can be carried by an individual photon when using this approach. Moreover, by making use of hyper-entanglement, one can encode simultaneously in several degrees of freedom, to increase data rates still further.

As attractive as OAM-QKD is, there are several challenges to its full deployment that REU students can help address as part of this research effort. (1) Continue to perfect our working OAM-QKD system by improving the various elements of this system, such as the OAM sorter and bright sources of entangled photons. (2) Paying close attention to developing means to mitigate the effects of propagation through severe atmospheric conditions. (3) Developing means to avoid the issue of long dead times associated with the use of APDs in QKD systems.

Epsilon-Near-Zero Materials: How Light Behaves When the Refractive Index Vanishes.

In this project we will explore some of the many unusual properties that light displays when propagating through a material with a vanishing or near vanishing refractive index. As one example, the properties of radiative processes such as spontaneous and stimulated emission are profoundly modified. In addition, the description of nonlinear optical processes is modified in these vanishing-index materials. Huge enhancements of the nonlinear optical response are predicted and observed from light at the zero-index wavelength of the material these materials. This huge enhancement has important implications for applications in photonics.

Summer projects will include performing measurements of the nonlinear optical response of these materials using both Z-scan, four-wave mixing, and spectral broadening approaches.

This work will apply a new method of polarization measurement to the characterization of the polarization of very small numbers of photons and will seek to apply this method to novel quantum states of light.

Optical metrology for photonic systems

This work, carried out in conjunction with AIM Photonics, seeks to apply new quantitative imaging methods to solve difficult packaging and assembly problems for integrated photonics.

The Cardenas Lab works on the next generation of integrated photonic technologies to revolutionize how we do things and how we probe the inner workings of our world. We are working on chip scale lasers based on 2D materials as the gain medium. Most laser technologies are not compatible with microelectronics manufacturing methods. Our work seeks to enable large-scale integration of lasers on chip scale platforms that are compatible with microelectronics fabrication.

Have you ever wondered if a chain of single atoms can control the direction in which light propagates? Our group is exploring this limit by developing waveguides (like an electrical wire for light, such as an optical fiber) that are atomically thin. Theory predicts that even at such thicknesses we should be able to guide the light.

One of the biggest challenges in getting photonic devices into your home is how we package photonics, electronics, and optical fibers together. We are developing new technologies for attaching fibers to photonic and electronic packages and for distributing light between chips.

For the summer, you will work on a project central to our goal of revolutionizing science and technology through integrated photonics. The project will be on an area such as the ones we just described. We will sit down and discuss your interests and tailor a project to suit your goals and skills as well as our group’s needs.

Femtosecond (fs) lasers have become an effective tool for material functionalization and precision engineering. In the past, our lab has dedicated in creating a range of techniques to functionalize materials, rendering regular surfaces super-absorptive or -emissive, superhy-drophillic or -hydrophobic. We have the following few research directions for REU projects.

Laser processing and imaging

The first REU research direction is to help us to develop more advanced laser processing techniques that allow us to obtain highly controllable sub-wavelength structures. In addition, we also have a project on developing optical imaging techniques to study ultrafast surface dynamics, such as laser-driven surface melting and resolidification.

Functionalized surfaces for solar applications

The second REU research direction is to apply the functionalized surfaces in a range of energy applications. Some current projects include utilizing our highly absorptive surfaces for solar energy collection and building thermal electric generators, and developing cooling devices utilizing the special wetting properties of the materials we produced.

Topics in nanophotonics

The third REU research direction is in the broad area of nanophotonics. Some current projects include developing high-transmission plasmonic meta-surfaces, thin-film photonics, engineering low-dimensional materials through metamaterials, and full single-photon wavefunction characterization in quantum optics.

Advances in quantum information science (QIS) require overcoming fundamental and technological challenges that occur at the intersection of materials science, physical chemistry, condensed matter physics, and optics. Of particular interest in QIS is the ability to engineer integrated nanophotonics systems that support both confined electronic and optical modes resulting in facile control over enhanced light-matter interactions.

An REU experience in this area can lead to several different research projects depending on the interest of the student. For example, in one project ultrafast optical spectroscopy is being used to study the photophysical properties (such as quantum coherence) between electrons in zero and one dimensional nanostructures that are strongly coupled to an optical cavity. In another project, single molecule fluorescence microscopy methods are applied to studies of the photochemical properties of molecules strongly coupled to an optical cavity. These studies are particularly unique in that they will represent one of the first experimental tests of theoretically predicted enhanced chemical reaction rates inside a couple matter-optical cavity system.

One potential REU research project in the Miller group will center on understanding the optical behavior of polymer microgel particles deposited on antireflective coatings. In preliminary work, we have used these materials to make sensitive multiplex biosensors, derivatizing individual microgel particles with antibodies to targets of interest. It is important to understand how polymer composition, particle size, and deposition density impact the observed reflectance signal indicative of binding. Undergraduates participating in this project will learn principles of thin film characterization (principally ellipsometry and interferometry), bioconjugation strategies, and dynamic light scattering.

The goal of this research project is to aid in the development of optics for emerging applications in solar concentrators and non-imaging lighting systems. Duncan T. Moore's research group is developing designs utilizing multi-layer optical arrays that are based on cutting edge manufacturing methods. This project entails aiding graduate students with fabricating and testing prototypes in a laboratory environment. Optical materials will also be researched and tested in the lab. There may be some work involving 3D printing, MatLab, Labview, and/or other optical design software packages.

Scattering of biological tissue makes deep imaging impossible for traditional fluorescence microscopy. Nonlinear optical microscopy overcomes this limitation because nonlinearly generated photons from a focus can be readily assigned to their origin. Nonlinear imaging is a crucial tool needed for a comprehensive understanding of the human brain, for example. However, current optical sources needed for this advanced technology are limited and expensive. The REU student will help design robust and high-performance ultrashort pulsed optical sources designed for advanced biomedical technologies. These systems involve complex nonlinear optical dynamics and the research will include both theoretical and experimental investigations.

The objective of this project is to bring biophotonics technology developed in our laboratory to fruition solving health care challenges. Students are involved in developing new parts of instrumentation or upgrades to some others in addition to looking into applications for which they may develop custom software. Some of the applications we have been investigating include guiding Mohs surgery (a surgical procedure performed in dermatology to remove cancer), non-invasive corneal imaging for ophthalmology, mapping of the elastic properties of tissues such as corneal and brain tissues, and mapping the physical properties of engineered tissue. All these projects involve strong collaborations with faculty across campus, including the Medical Center.

Name: Geunyoung YoonDepartment: Ophthalmology / The Institute of OpticsResearch area:Vision and the Eye

Project Descriptions:

Advanced Vision Correction

It has long been known that the human eye is optically imperfect. Ocular wavefront sensing technology that quantifies optical properties of the eye makes it possible to compensate for the optical defects in the eye. The project involves various advanced correction methods developed in the laboratory including a binocular adaptive optics vision simulator, wavefront-guided ophthalmic lenses and individualized laser refractive surgery. This capability opens a new opportunity to study how the optics of the eye influences neural processing and visual perception.

Presbyopia

Presbyopia, or age-related near vision loss, is a visual condition that affects all adults over the age of 40 and there is no way to reverse this normal aging process. Due to limited daily life activities imposed by traditional optical aids such as reading glasses, developing robust solutions to overcome the problem is of great importance to improve quality of life. The long-term objective of the project is to develop a new intraocular lens that can be implanted into the eye to restore accommodation. This multidisciplinary study involving, optics, mechanics and ophthalmology is conducted with 3-D CAD, finite element modeling and optical metrology.

Dry eye disease (DED) is common and adversely affects quality of life. Using instruments built with scientific-grade cameras and components customized for ocular applications, our group has demonstrated that statistically significant clinical sub-classifications of dry eye can be determined objectively and non-invasively using independent, non-simultaneous polarimetric lipid imaging and thermal imaging. This project will use the results of this previous research to build and test clinical prototypes that use commercially available components to characterize the lipid layer and aqueous tear layers.

Low-cost imaging of breast specimen tissue regions

Our research group has developed a combination of spectral and polarization macroscopic imaging that optically distinguishes between adipose and collagen tissues in clinical breast tissue specimens, thus highlighting regions suspected of containing epithelium in order to facilitate optical microscopy techniques. The color signature of adipose tissue can be used to determine regions of adipose tissue while collagen is located using intrinsic birefringent signatures. This project proposes to build a breast specimen imaging system utilizing optical components from a consumer flatbed scanner to assess the tissue composition of breast cancer specimens.